A challenged book is one that is sought to be removed or otherwise restricted from public access, typically from a library or a school curriculum. This is a list of the most commonly challenged books in the United States. It is primarily based on data gathered by the American Library Association's Office for Intellectual Freedom (OIF). The OIF gathers their data from media reports from reports from librarians and teachers.[1]

According to the OIF, the top three reasons for challenging such materials were that they contained "sexually explicit" content, "offensive" language, or were "unsuited to any age group".[2]

Note: The ALA Office for Intellectual Freedom (OIF) does not claim comprehensiveness in recording challenges. Research suggests that for each challenge reported there are as many as four or five which go unreported.[7]